Diaz went 0-for-3 with a strikeout in Wednesday's Grapefruit League game against the Yankees.
The 23-year-old is expected to begin the season as the Marlins' starting second baseman, but he isn't exactly seizing the opportunity this spring. Diaz is slashing .103/.235/.103 through 34 plate appearances with a 5:9 BB:K, and if his struggles at the plate extend past Opening Day, Jon Berti could begin to cut into his playing time at the keystone.